On the last attack, the combined British and Hessian troops concentrated on the right wing. The Hessians attacked with fixed bayonets, and the First Rhode Island regiment stopped them and counterattacked. With the fighting so close and intense, there was no time to reload and steel clanged against steel. The field was strewn with the dead and wounded from both sides as the Americans rallied and routed the enemy. They emerged victorious and the British abandoned the field, leaving their dead and wounded.

On August 30, Sullivan received bad news. Lord Howe and the British fleet had been sighted off Block Island and were heading for Newport. All American officers concurred that there was no alternative but to retreat. The withdrawal from the island was in itself a major accomplishment. Sullivan ordered his men to pitch tents to give Pigot the impression that he was preparing for another battle. Under this cover he managed to remove all the heavy equipment from the island. Then, when darkness made it possible, General Cornell and Major Talbot were able to get the entire army safely across the Seaconnet to Tiverton. Not a man was left behind nor an article lost.

Sullivan reported 211 Americans killed, wounded and missing, while Pigot admitted to 260 British casualties. Eyewitness accounts place the figures much higher, and the American estimate is that there were 1,023 British and Hessian soldiers killed or wounded.

Both the Continental Congress and General Assembly were lavish in their praises for Generals Sullivan and Greene and for the Rhode Island troops who fought in this battle. Unfortunately, it did not provide the victory that George Washington had hoped for, but it did prove that American generals and troops could be matched against the highly trained British and Hessian soldiers. Sullivan was never able to muster up another army large enough to drive the British from Newport, but the battle of Rhode Island was a key factor in keeping the British from invading Providence and the mainland.